1. Field of the Invention
The invention pertains to a check valve, consisting of a housing, a bore, and a movable valve body, which is spring-loaded and rests with a sealing action on a valve seat, where the bore is designed as a stepped bore, and where the bore with the smaller diameter has the valve seat and the bore with the larger diameter holds the movable valve element.
2. Description of the Related Art
Check valves are already known (DE 40 25 488 C2) in which a movable valve element is provided, where a ball-shaped valve body is provided at least in the area of the valve seat. A closing spring keeps this valve body under pretension. A movable cylindrical part and a stationary cylindrical part, furthermore, create an annular space, the volume of which changes with the movement of the inner parts. The action of the valve can thus be damped by way of a throttle bore. Check valves of this design, especially those with a valve ball or a segment of a ball, operate very precisely in principle, but their disadvantage is that a large mass must be moved, and the valve thus cannot react quickly enough for high-frequency actuations. To avoid contact noises, therefore, a check valve of this type is preferably damped.
This design also occupies a considerable amount of space and, simply because of the number of individual parts and their shapes, it is unsuitable for completely automated assembly.